Water-soluble binders for paper coating slips

Abstract

Paper coating slips comprising a) one or more binders b) if appropriate, a thickener c) if appropriate, a fluorescent or phosphorescent dye, in particular as an optical brightener d) pigments or fillers e) further assistants, e.g. leveling agents or other dyes, wherein at least 40% by weight of the total amount of the binders a) comprise a synthetic, water-soluble, anionic polymer (anionic polymer for short) and less than 50% by weight of the total amount of the binders a) are emulsion polymers.

1 : A paper coating slip comprising
 a) one or more binders;   b) optionally, a thickeners   c) optionally, a fluorescent or phosphorescent dye, as an optical brightener;   d) pigments or fillers; and   e) further assistants selected from the group consisting of leveling agents and other dyes,   wherein at least 40% by weight of the total amount of the binders a) comprise a synthetic, water-soluble, anionic polymer and less than 50% by weight of the total amount of the binders a) are emulsion polymers.   
   
   
       2 : The paper coating slip according to  claim 1 , wherein the anionic polymer comprises at least 0.01 mol of acid groups per 100 g of anionic polymer, and at least 20 mol % of the acid groups are present as a salt. 
   
   
       3 : The paper coating slip according to  claim 1 , wherein the solubility of the anionic polymer in water is greater than 50 g of polymer/1 liter of water at 21° C. and 1 bar. 
   
   
       4 : The paper coating slip according to  claim 1 , wherein the anionic polymer is a polymer obtained by the free radical polymerization of ethylenically unsaturated monomer compounds. 
   
   
       5 : The paper coating slip according to  claim 1 , wherein at least 10% by weight of the monomers of which the anionic polymer is composed are acid monomers which comprise acid or salt groups. 
   
   
       6 : The paper coating slip according to  claim 1 , wherein the acid monomers are selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, and itaconic acid. 
   
   
       7 : The paper coating slip according to  claim 1 , wherein the anionic polymer is additionally composed of at least 5% by weight of further monomers selected from ether monomers having at least one ether group or nitrogen monomers having at least one nitrogen atom. 
   
   
       8 : The paper coating slip according to  claim 1 , wherein the nitrogen monomers are selected from the group consisting of vinylformamide, (meth)acrylamide, vinylpyrrolidone and vinylimidazole. 
   
   
       9 : The paper coating slip according to  claim 1 , wherein the anionic polymer is a polymer composed of
 from 5 to 95% by weight of acid monomers which comprise acid or salt groups,   from 5 to 95% by weight of nitrogen monomers selected from the group consisting of vinyl formamide, (meth)acrylamide, vinylpyrrolidone and vinylimidazole; and   from 0 to 30% by weight of auxiliary monomers.   
   
   
       10 : The paper coating slip according to  claim 1 , wherein more than 60% by weight of the binders a) comprise an anionic polymer. 
   
   
       11 : The paper coating slip according to  claim 1 , wherein less than 20% by weight of the binders a) are emulsion polymers. 
   
   
       12 : The paper coating slip according to  claim 1 , comprising no emulsion polymers as binders. 
   
   
       13 : The paper coating slip according to  claim 1 , wherein the amount of the binder a) is from 1 to 50 parts by weight per 100 parts by weight of pigments or fillers d). 
   
   
       14 : A composition for coating paper and cardboard comprising the paper coating slip according to  claim 1 . 
   
   
       15 : A paper or cardboard coated with a paper coating slip according to  claim 1 .